CHEM 3050 Study Guide - Fall 2018, Comprehensive Midterm Notes - Enzyme, Adenosine Triphosphate, Pyruvic Acid
11 Oct 2018
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CHEM 3050
MIDTERM EXAM
STUDY GUIDE
Fall 2018
CHEM 3050
Lecture 1
ENZYME DYNAMICS & FUNCTION
Living things need to harness energy from the environment in order to carry
out the reactions required for life. Plants use sunlight, we eat food. The
focus of biochemistry and metabolism can be broken down to three
metabolic processes every cell goes through
1) Glycolysis the preferred method of energy harnessing; it is the
breakdown of glucose to pyruvate. Works nicely because carbs are
fastest/most used energy source
2) The citric acid cycle generation of acetyl Co-A; kind of the hub of
metabolism where intermediates are made for other structural
components/processes and where further energy is harnessed
3) Oxidative phosphorylation final step in harnessing energy from food.
By these processes, glucose can be harvested for more than just energy
use; it can be harnessed for use in structural situations (molecular
interactions, cellular structure, etc) and used to make other important
biomolecules (nucleic acids, glycogen, etc)
Even still sugar/glucose is the most direct/efficient input into the energetics
metabolic pathway.
Step 1: Glycolysis
Directly breaking the sugar up; use D-glucose, 2 NAD+(oxidized) & 2 ADP
2 pyruvate, 2 NADH (reduced) & 2 ATP in an overall favourable process
ΔG°’: -29.9kJ/mol
find more resources at oneclass.com
find more resources at oneclass.com
Still involves steps that require energy/not favourable
There are other pathways called feeder pathways that feed into glycolysis
from other energy sources either by producing glucose or producing
intermediates in glycolysis
Takes place by ten reactions in 2 phases
Phase 1: The Preparation
ΔG°’: 2.1 kJ/mol per molecule of glucose, up until the production of GAP
Step 1: Hexokinase
Glucose is activated by hexokinase in a Mg2+ dependent reaction that
phosphorylates it to G6P (glucose-6-phosphate) in a favorable reaction
ΔG° = -20 kJ/mol; this prevents glucose from leaving the cell, promoting
glucose uptake
Step 2: G6P Isomerase aka Phosphohexose Isomerase
Catalyzes ene-diol rearrangement of the pyranose to a furanose ring; the
anomeric carbon is mobile in solution, can be in equilibrium with alpha/beta
anomers both will work; The enzyme makes use of Glu and His338 in
the opening and closing of the ring. His opens and closes the ring and
Glu acts as base and attacks proton at C2;
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Living things need to harness energy from the environment in order to carry out the reactions required for life. The focus of biochemistry and metabolism can be broken down to three metabolic processes every cell goes through: glycolysis the preferred method of energy harnessing; it is the breakdown of glucose to pyruvate. By these processes, glucose can be harvested for more than just energy use; it can be harnessed for use in structural situations (molecular interactions, cellular structure, etc) and used to make other important biomolecules (nucleic acids, glycogen, etc) Even still sugar/glucose is the most direct/efficient input into the energetics metabolic pathway. Directly breaking the sugar up; use d-glucose, 2 nad+(oxidized) & 2 adp. 2 pyruvate, 2 nadh (reduced) & 2 atp in an overall favourable process. There are other pathways called feeder pathways that feed into glycolysis from other energy sources either by producing glucose or producing intermediates in glycolysis. Takes place by ten reactions in 2 phases.
